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The hyperbolic partial differential equation (PDE) has important practical uses in science and engineering. This article provides an estimate for solving the Goursat problem in hyperbolic linear PDEs with variable coefficients. The Goursat PDE is transformed into a second kind of linear Volterra in-tegral equation. A convergent algorithm that employs Taylor polynomials is created to generate a collocation solution, and the error using the maxi-mum norm is estimated. The paper includes numerical examples to prove the method’s effectiveness and precision.

Introduction: This study explores the therapeutic potential of silver nanoparticles (Ag NPs) synthesized using a Helianthemum lippii extract in mitigating cadmium-induced hepatotoxicity in Wistar rats. Given the increasing environmental and health concerns associated with cadmium exposure, novel and eco-friendly therapeutic strategies are essential.Methods: Ag NPs were characterized using X-ray diffraction, UV-Vis spectrometry, and energy-dispersive X-ray spectroscopy with scanning electron microscopy, confirming their formation with a cubic crystal structure and particle sizes ranging from 4.81 to 12.84 nm. A sub-acute toxicity study of Ag NPs (2 mg/kg and 10 mg/kg) was conducted, showing no significant difference compared to untreated control rats (n = 3 animals/group). Subsequently, adult Wistar rats (n = 5/group) were divided into a control group and three experimental groups: Ag NPs alone, exposure to 50 mg/kg CdCl2 in drinking water for 35 days, and CdCl2 exposure followed by 0.1 mg/kg/day Ag NPs intraperitoneally for 15 days.Results: In the CdCl2-exposed group, there was a significant decrease in body weight and increases in alanine and aspartate transaminase levels (p < 0.05 vs. control), indicating hepatotoxicity. Additionally, antioxidant defenses were decreased, and malondialdehyde levels were elevated. Liver histology revealed portal fibrosis, inflammation, necrosis, sinusoid and hepatic vein dilation, and cytoplasmic vacuolations. Treatment with Ag NPs post-CdCl2 exposure mitigated several adverse effects on liver function and architecture and improved body weight.Discussion: This study demonstrates the efficacy of Ag NPs synthesized via a green method in reducing cadmium-induced liver damage. These findings support the potential of Ag NPs in therapeutic applications and highlight the importance of sustainable and eco-friendly nanoparticle synthesis methods. By addressing both toxicity concerns and therapeutic efficacy, this research aligns with the growing emphasis on environmentally conscious practices in scientific research and healthcare.

Deterioration of treated drinking water intended for consumption during distribution may be due to physical, chemical or microbiological changes that occur in the water. In addition, the type of pipe material and disintegration of a disinfectant agent can affect the quality of the water supplied. Therefore, the research approach is to simulate the decay residual Cl2 through potable water distribution networks produced by a desalination plant of Oran city in western Algeria. EPANET 2.0 software was used for estimating and predicting Cl2 concentration at different water network points. The value of bulk flow decay coefficient (Kb) is set to −1,99 day−1 for a 50-year-old steel pipe, value for the wall decay coefficient (Kw) was determined using a trial-and-error procedure and assumed to be −1,2 day−1.

Working with recent isolates of human cytomegalovirus (HCMV) is complicated by their strictly cell-associated growth with lack of infectivity in the supernatant. Adaptation to cell-free growth is associated with disruption of the viral UL128 gene locus. The authors transduced fibroblasts with a lentiviral vector encoding UL128-specific-shRNA to allow the release of cell-free infectivity without genetic alteration. Transduced cells were cocultured with fibroblasts containing cell-associated isolates, and knockdown of the UL128 protein was validated by immunoblotting. Cell-free infectivity increased 1000-fold in isolate cocultures with UL128-shRNA compared with controls, and virions could be purified by density gradients. Transduced fibroblasts also allowed direct isolation of HCMV from a clinical specimen and cell-free transfer to other cell types. In conclusion, UL128-shRNA-transduced fibroblasts allow applications previously unsuitable for recent isolates.

This study explored the therapeutic efficacy of Helianthemum lippii and silver nanoparticles (Ag NPs) synthesized using a H. lippii extract to alleviate cadmium-induced nephrotoxicity in Wistar rats. Sub-acute toxicity assessments of H. lippii (100 mg/kg, 1000 mg/kg, and 4000 mg/kg) and Ag NPs (2 mg/kg and 10 mg/kg) did not find any significant difference, compared with untreated control rats (n = 3 animals/group). Then, the adult Wistar rats were divided into one control (untreated/unexposed) and six experimental groups (n = 5/group): Ag NPs alone, H. lippii alone, exposure to 50 mg/kg CdCl2 in drinking water for 35 days, exposure to CdCl2 for 35 days followed by treatment with 0.1 mg/kg/day Ag NPs (intraperitoneal injection) and/or 100 mg/kg/day H. lippii by gavage for 15 days. In the CdCl2-exposed group, body weight decreased; urea, creatinine, and uric acid concentrations increased (p < 0.05 vs. control), indicative of nephrotoxicity, antioxidant defenses (SOD, GSH, and CAT) were reduced, and malondialdehyde concentration increased. Moreover, the kidney’s architecture in CdCl2-exposed rats was altered: fibrosis, inflammatory cell infiltration, glomerular destruction, and tubular dilatation. Treatment with H. lippii and/or Ag NPs after CdCl2 exposure improved some of the renal function and architecture alterations induced by CdCl2, and also increased body weight. This study underscores the potential therapeutic applications of H. lippii and Ag NPs to decrease oxidative stress and promote xenobiotic detoxification, in line with the growing emphasis on environmentally conscious practices in scientific research and healthcare.

Introduction. Pediatric asthma is predominantly atopic, but no data are found on atopy in obese asthmatic child in the literature. In addition, the increased obesity rates, sensitization to airborne allergens are a risk factor for asthma. Objective. To determine whether elevation of body mass index (BMI) was associated with asthma severity or with sensitization to inhalation allergens in adolescents in the wilaya of Constantine. Material and methods. This was a prospective, descriptive and cross-sectional study, carried out during the 2017-2018 school year, on 104 asthmatic adolescents, aged between 13 and 14, in schools in Constantine. The weight status of the patients was assessed using the 2012 thresholds of the International Obesity Task Force (IOTF), and a BMI ≥ 25 kg/m2 defined overweight or obesity. Asthmatics obese and non-obese groups were compared for the prevalence of severe asthma and sensitization using the Chi-square test, at the 95% confidence interval. Results. Twenty-five per cent of asthmatics were overweight or obese with an average BMI of 28,20±3,80. Asthma symptoms were persistent in 66%, and uncontrolled in 40% of cases. Almost 70% of the population were atopic, and 50% were poly-sensitized. Sensitization occurred in both groups with a significant positive ratio (p=0.03). No association was observed between obesity and prevalence of severe asthma (p=0.5), or poly-sensitizations. Conclusion. The quarter of adolescents is overweight or obese, and tends to present an atopy. However, no positive association is found between obesity and prevalence of severe asthma symptoms. Further prospective studies are needed for a better understanding of this obese asthmatics group. [Résumé Introduction. L’asthme pédiatrique est majoritairement atopique, mais aucune donnée n’existe sur l’atopie de l’enfant asthmatique obèse dans la littérature. En outre, l’élévation du taux d’obésité, la sensibilisation aux pneumallergènes sont un facteur de risque pour l’asthme. Objectif. Déterminer si l’élévation de l’indice de masse corporelle (IMC) est associée à la sévérité de l’asthme ou à la sensibilisation aux pneumallergènes, chez des adolescents asthmatiques dans la wilaya de Constantine. Matériel et méthodes. Une étude prospective, descriptive et transversale est réalisée durant l’année scolaire 2017-2018, et a porté sur 104 adolescents asthmatiques, âgés entre 13 et 14 ans, au sein des établissements scolaires de Constantine. Le statut pondéral des malades a été évalué en utilisant les seuils de l’International Obesity Task Force (IOTF), avec un indice de masse corporelle (IMC) ≥ 25 kg/m² définissant le surpoids ou l’obésité. Des groupes d’asthmatiques obèses et non obèses ont été comparés afin de noter la prévalence de l’asthme sévère et la sensibilisation en utilisant le test de Chi-deux à l’intervalle de confiance de 95 %. Résultats. Un quart des asthmatiques étaient en surpoids ou obèses avec un IMC moyen de 28,20±3,80. Les symptômes d’asthme étaient persistants chez 66%, et non contrôlés chez 40% des cas. Près de 70% de la population était atopique et 50 % étaient polysensibilisés. La sensibilisation s’est produite dans les deux groupes avec un rapport positif significatif (p=0,03). Aucune association n’est observée entre l’obésité et la prévalence de l’asthme sévère ou les poly-sensibilisations. Conclusion. Le quart des adolescents sont en surpoids ou obèses et ont tendance à présenter une atopie. Cependant, aucune association n’est notée entre l’obésité et la prévalence des symptômes sévères d’asthme. D’autres études prospectives sont nécessaires pour une meilleure compréhension du groupe d’asthmatiques obèses.]

Eliminating the excessive stick–slip torsional vibrations of drill strings by utilizing an effective controller can significantly increase penetration rates and reduce drilling operation costs. The present study aims to develop a fast and intelligent cascade control structure for a multi-degree-of-freedom drill string system under torsional vibrations. The proposed control configuration consists of two control loops in a cascade arrangement. The first controller estimates the top drive velocity reference from the actual drill bit velocity and its reference. The role of the second controller is to regulate the top drive velocity to its reference by generating the necessary torque for the drilling operation process to progress. Each control loop is designed based on a hybrid adaptive neuro-fuzzy PID and feedforward term. The latter assures fast regulation when there are sudden changes in operation. To evaluate the performance of the suggested cascade feedforward neuro-fuzzy PID (CFF-NFPID) control structure, extensive simulations were conducted using Matlab/Simulink. The simulation results clearly showed that the proposed CFF-NFPID controller provided high-performance control with variations in the weight on the bit and the desired drill bit rotary speed in comparison with that of cascade feedforward fuzzy PID, sliding-mode, cascade feedforward PID, cascade PID, and conventional PID controllers. Furthermore, the control robustness is very suitable despite the change in the system parameters.

The electrochemical proton exchange membrane fuel cell (PEMFC) is an electrical generator that utilizes a chemical reaction mechanism to produce electricity, serving as a sustainable and environmentally friendly energy source. To thoroughly analyze and develop the features and performance of a PEMFC, it is essential to use a precise model that incorporates exact parameters to effectively suit the polarization curve. In addition, parameter extraction plays a crucial role in the simulation analysis, evaluation, optimum control, and fault detection of the proton exchange membrane fuel cell (PEMFC) system. Despite the development of many algorithms for parameter extraction in PEMFC, obtaining accurate and trustworthy results rapidly remains a challenge. This study presents a hybridized algorithm, namely differential evolution ameliorated (DEA) for reliably estimating PEMFC model parameters. To evaluate the proposed DEA-based parameter identification, a comparison analysis with previously published methods is conducted using MATLAB/SimulinkTM (R2016b, MathWorks, Natick, MA, USA) in terms of system correctness and convergence process. The proposed DEA algorithm is tested to extract the parameters of two PEMFC models: SR-12 500 W and 250 W. The sum of the squared errors (SSE) between the experimental and the obtained voltage data is defined as an objective function. The simulation results prove that the suggested DEA algorithm is capable of identifying the optimal PEMFC parameters rapidly and accurately in comparison with other optimization algorithms.

Information has shown to be the weapon on which global economic institutions depend, namely with the intensification of competition and the rapid technological development that the world is nowadays witnessing in light of the digital information revolution. Thus, lots of negative aspects came into sight from the use of such digital revolution on the consumer, most notably the information pollution as regards various products, the issue of which will be addressed in our present study, as we aim to shed light on the information pollution in the digital environment and its impact on the consumer behaviour, together with identifying the causes and risks thereof. In closing, we will bring to mind the mechanisms and the ways to protect the consumer from such type of pollution. We conducted a field study that included a sample of 305 interrogated individuals for consolidation purpose of the obtained results.

Introduction. For AC-DC conversion systems, the electrical systems typically use thyristor or diode bridge rectifiers, which have relatively poor performance. Nowadays, three-phase pulse-width modulation rectifiers are widely applied in various applications for their well-known intrinsic benefits, such as adjustable DC link voltage, unity power factor, bidirectional power flow and very low total harmonic distortion. Purpose. The objective of this work is to achieve better stability and dynamic performance using sliding mode strategy for control and observation. Methods. For that purpose, first a sliding mode controller is introduced on the DC-link side to ensure a fast and accurate response of the output load voltage. Then, the sliding mode approach is employed to control the quadrature and direct components of power to maintain the input power factor at unity. Finally, this approach is used to design two observers for grid voltage estimation and online variation of load resistance. To overcome the problem associated with the use of the classical low-pass filter, an adaptive compensation algorithm is used to compensate the attenuation of the amplitude and phase delay of the observed grid voltages. This algorithm is based on the use of the two low-pass filters in cascade and ensures the minimization of chattering. Results. Comparative studies have been carried out between sliding mode control method for controlling the three-phase AC-DC pulse-width modulation rectifier and other conventional techniques. The validation by simulation and the tests carried out gave very satisfactory results and proved the effectiveness and feasibility of the sliding mode for both control and observation of three phase pulse-width modulation rectifier.

Monitoring air quality is gaining popularity in the research community since it can help policymakers make the right decisions for mitigating the negative effects of the ever-increasing pollution in cities. One of the significant sources of air pollution in urban areas is road transport. Assessing and understanding the relationship between urban traffic and local pollutants is crucial to maintaining sustainable urban mobility. This paper presents an exploratory data analysis of air pollution and traffic in some cities in Luxembourg. Furthermore, we studied the link that several pollutants have with other parameters, such as temperature and humidity. The paper also focuses on traffic and offers more insights for sustainable urban mobility.

Abstract Background The effect of age on the bone mineral density and microarchitecture of the equine radius and tibia was investigated. Fifty-six bones from 15 horses aged four to 21 years were used. There were nine geldings and six mares, and none of the horses had any disease influencing bone properties. Xtreme computed tomography was used to evaluate a 9-mm segment of the diaphysis and metaphysis of each bone. The following variables were determined: length of the bone, circumference and diameter in the frontal and sagittal planes in the middle of the bone. Diaphysis: total volume, bone volume, bone volume ratio, slice area, bone area, marrow area, cortical and marrow thickness, bone mineral density, polar moment of inertia of the cortex. Metaphysis: total area, bone area, cortical bone area, cortical thickness, bone mineral density, bone mineral density in the cortex, bone mineral density in the trabecular region, trabecular number, trabecular thickness, trabecular separation, polar moment of inertia of the metaphysis, polar moment of inertia of the cortex of the metaphysis. Results Bone density and microarchitecture were not affected by breed or gender. However, the microarchitecture varied with the age of the horse; the number of trabeculae decreased significantly and the distance between trabeculae increased significantly with increasing age. There were no significant differences between bones of the left and right limbs or between the radius and tibia. Conclusion The variables investigated did not differ between geldings and mares. However, there were age-related changes in the microstructure of the bones. Further experimental studies are necessary to determine whether these changes reduce bone strength. Age-related changes in the bones were seen and may explain the higher incidence of fractures and fissures in older horses.